Electronic devices have become slimmer in order to meet consumers' needs as the functional gap therebetween has significantly decreased. Electronic device makers have made efforts to make electronic devices slim while increasing the rigidity thereof and improving the design. Reflecting this trend, the electronic devices have been developed to efficiently ensure an arrangement space of at least one antenna device that is necessarily required for communication among elements thereof in order to prevent degradation in radiation performance and to achieve an excellent performance.
Antenna devices used in electronic devices have an inverted-F antenna (IFA) or a monopole radiator as a basic structure, and a volume and/or a number of antenna radiators to be mounted may be determined according to frequency, bandwidth, and a type of each service. For example, although there is a difference in frequency between areas in the world, a low band of 700 megahertz (MHz) to 900 MHz, a mid-band of 1700 MHz to 2100 MHz, a high band of 2300 MHz to 2700 MHz, and the like are generally used as major communication bands. Additionally, various wireless communication services are used, such as Bluetooth (BT), global positioning system (GPS), WIFI, etc. However, it is difficult to ensure all the bands with only a single antenna in reality. Accordingly, in order to overcome the problems, multiple antennas are separately designed by collecting service bands (e.g., similar frequency bands) to satisfy all the aforementioned communication bands in a limited antenna volume of a given communication device.
For example, an antenna that performs voice/data communication (e.g., general packet radio service (GPRS), wideband code division multiple access (WCDMA), long term evolution (LTE), etc.)), which is the major communication system of a terminal device, may be located on a lower end portion of the terminal device where a small number of metal components that deteriorate the performance of the antenna are mounted. Based on the European standard, a total of 24 bands, including 2G (global system for mobile system (GSM) 850, extended GSM (EGSM), digital communication system (DCS), and personal communication system (PCS)), WCDMA (B1, B2, B5, and B8), LTE (B1, B2, B3, B4, B5, B7, B8, B12, B17, B18, B19, B20, B26, B38, B39, B40, and B41), etc., have to be implemented. In fact, since it is difficult to satisfy service provider specifications and the specific absorption rate (SAR) standard and to minimize effects on human bodies while implementing all the bands with a single antenna, antennas may be implemented by collecting service bands having similar frequency bands over at least two areas. By way of example, 2G (GSM850, EGSM, DCS, and PCS), WCDMA (B1, B2, B5, and B8), and LTE (B1, B2, B3, B4, B5, B8, B12, B17, B18, B19, B20, B26, and B39) may be implemented with one antenna, and LTE (B7, B38, B40, and B41) may be implemented with another antenna.
Further, in a case where an exterior of an electronic device is constituted by a metal member (e.g., a metal bezel, etc.) in order to meet a recent trend, an antenna may not be separately designed, as opposed to a dielectric injection-molded material, and may be designed by making use of the metal member as an antenna radiator.
For example, in a case where a metal member arranged on the outer periphery of an electronic device is used as an antenna radiator, specific locations of the metal member are cut off by dielectric cut-off portions in order to adjust a physical length from a feeding part to the antenna, thereby enabling the antenna to operate in a desired frequency band.
In this case, a ground part has to be disposed in a corresponding position of the metal member in order to enable the metal member to operate in the desired frequency band, but there is a difficulty in that a mounting space has to be provided in order to add a separate electrical connection member (e.g., a C-clip, a conductive gasket, etc.) for a physical contact between the outer periphery of the metal member and the ground part of a printed circuit board (PCB).